2-wheel-drive (2WD) Ford F-150 trucks are great if you want to pay less for gas and insurance. But, when you want to do more substantial work such as towing, hauling, or just want to go off-roading, what are the conversion possibilities? Luckily, there are several ways to convert a 2WD F-150 to 4WD.
Can you convert a 2WD F-150 to 4WD? There are two main options for you to convert an F-150 from 2WD to 4WD. Either keep the original IFS (Independent Front Suspension) or scrap the IFS for an SFA (Solid Front Axle). Either way, it takes scrapyard parts and time to install the parts and tune them.
2WD to 4WD conversion on a Ford F-150
Both of the options I explained above are not ideal and will cost money and time. But, if you have spent a lot of money on a truck with loan payments, are interested in a project, or just love your F-150 too much to let it go for another, this short guide should help…
What is IFS vs. SFA?
The two main types of suspension for a 4×4 F-150 have heavily debated topics. There are dozens of forums on the comparison between the two. But, if evidence of a shift from major manufacturers like Jeep tells us anything, it is that IFS is winning out as more versatile and better for off-road conditions.
Take, for example, the line of Jeep vehicles that, up until 2001, were entirely made with SFA. The conversion from SFA to IFS included some of the best 4×4 vehicles on the road: Wrangler TJ, Grand Cherokee WJ, and Cherokee XJ. A shift away from FSA to IFS is seen in almost every Jeep now on the market in 2020.
SFA is a straightforward design for suspension that can handle rough conditions but gives a rough ride at all times. IFS simply can outperform the SFA in off-road and on-road conditions. Since IFS can exceed SFA, it has led to an increase in IFS in most stock 4×4 on the market today.
Let’s look at some of the pros and cons of each suspension system. The type of suspension used is essential to consider before detailing how to convert a 2WD F-150 to a 4WD.
What are the pros and cons of SFA?
SFA of a stable front axle suspension is simplistic. Let’s look at some of the pros and cons of SFA.
Pros of SFA
- More durable and stronger design than IFS.
- Better for certain terrains, such as rock crawling and off-road trails.
- More comfortable to work on and swap out.
Cons of SFA
- Rough riding that is not versatile.
- More head-tossing in the cab.
- Must drive slower to tackle off-road.
What are the pros and cons of IFS?
With many off-road vehicles moving to IFS as their stock and virtually all SUV are IFS, there is a reason that the pros for owning a 4×4 with IFS outweigh the cons. Here is a shortlist of the pros and cons of having a 4×4 with IFS:
Pros of IFS
- Left and right wheels not connected by a single steel beam make for a smoother ride.
- Better for those who spend a majority of their time driving on-road.
- Can drive over off-road at higher speeds.
- More ground clearance compared to an SFA.
Cons of IFS
- Harder to swap out or work on.
- Less articulation on-ramp than SFA.
- Harder (and more expensive) to work on because of the many moving parts of IFS.
Converting A 2WD F-150 To 4WD With An IFS
If you plan to keep the current IFS on your 2WD, there are a few more steps that you will need when converting a 2WD F-150 to 4WD. It will also cost a little bit more money. But, converting a 2WD F-150 to a 4WD with an IFS is possible.
Here are the steps to gather the parts you will need either from a salvage yard or buying them new:
Step #1: Front suspension
Strip all the front suspension from a salvage yard, including the 8.8 front differential and CV shafts.
Step #2: T-Case
You will need a Transfer Case(T-Case). A T-Case works the drivetrain on a 4×4. The transfer case is an integral part of the conversion because it will be the part that transfers transmission power to the front and rear axles. You may want to think about buying a new one.
Step #3: Front drive shaft
The drive shaft converts power from the T-Case into the front axle. Since this is such an integral part of your 4×4 drivetrain, here are a few things to look out for if you are salvaging a front driveshaft:
- Hard to turn truck
- Vibrating coming from under the truck
- Shuddering or vibrations when you accelerate
- Clunking noise that can sound very loud
- Squeaking, clicking, or knocking noises
Step #4: Hubs and spindles
Make sure to take the hubs and spindles from the salvage. Spindles are the inner workings of the axel that connect the axle to the wheel and hub.
Step #5: Front differential gear ratio
For the front differential to be functional, it will need to have the same gear ratio. You can pull the driveshaft off and look at the paint swab on top of the pinion. The color corresponds to the ratio on this chart.
Step #6: T-Case bolted to 2WD transmission
Bolting the T-case to the 2WD transmission may be a tight fit. You may need to fabricate it to bolt it on.
Step #7: Shorten the rear drive shaft
More than likely, you will need to shorten the rear driveshaft by several inches. Here is an excellent step by step guide that can help you with this detailed work on shortening a rear driveshaft.
Step #8: Sending unit types
There are two types of sending units that you can use. Either get an electrical or a manual sending unit. The sending unit will decrease the electrical current flow in and around the fuel tank.
Step #9: Wires and vacuum lines
You can purchase new vacuum lines through Ford for around $100. The primary function of the vacuum line and wires that go along with it is for the blue line to be running the vacuum when in 4WD and the pink line to be running when in 2WD.
Converting a 2WD F-150 to 4WD with an SFA
If you want to scrap the IFS for a more rugged SFA, there are several different steps to consider when converting your 2WD F-150 into a 4WD. However, there is less technical work than turning an IFS, which may take less time and money.
Step #1: Locate a solid front axel
The types of front axels that you can use on your F-150 are D44, D50, or D60. The Ford 9” is a standard that may also work for your front axle.
Step #2: Suspension setup
There are several ways to set up the suspension for your SFA.
- 4-link with coil-overs
- Radius arms and coil springs
- Leaf springs
Step #3: Ride height
Next, decide on the ride height that you want. Keep in mind that you need 8” of clearance for the cross-members.
Step #4: Welding
If you cannot do the welding yourself, you will need to find a 4×4 show that you trust to do it for you. Many decent shops should be able to make the bolt-on conversion for any axel of your choice, which might be more expensive than just having them weld it all on.
Step #5: T-Case
The T-Case that works the best for an SFA is the part ID# NP205. Make sure there are no clearance issues before installing the t-case.
Step #6: Wiring
Wiring a 4×4 can be tedious work. We suggest consulting a professional or to look at the schematics of the 4×4 for the F-150 to help guide you.
Step #7: Steering
There are several types of steering to choose from with SFA.
- Hydro assist steering
- Crossover steering
- High steer
Conclusion
A conversion from 2WD to 4WD on a Ford F-150 will be more difficult if you try to keep the IFS. There are more moving parts and steps to consider, not to mention the cost will be more. Although the IFS is superior for comfort when not on trails, the SFA is easier for this conversion and which is why I recommend it for someone trying to do the majority of the work themselves.
If you can take on the challenge of keeping the IFS during this conversion, you will have a more comfortable ride on the roads and around town.
Otherwise, consider converting to an SFA because of the more natural conversion steps.
Remember, SFA has many benefits. It is more rugged and stronger. It also can be worked on more quickly, so if you ever want to upgrade in the future, it will be easier to do so.
Take the time to consider the two types of 4WD suspensions and then make sure to check out the salvage yard before buying any new parts to save yourself some money!
